Process of making plates for storage batteries using lead suboxide



Patented May 11, 1-926.

UNITED STATES PATENT OFFICE.

ennzo snrmnnzu, on KYOTO, JAPAN.

r'nocnss or magma rna'rns non sronaen BATTERIES usme man sunoxmn.

No Drawing.

This invention relates to a process of manufacturing plates for storage batteries char or grids with a paste formed by kneading a lead oxide, such as litharge minium, to-

- gether with dilute sulphuric acid, but in such method, the chemical change that occlirs in the lead oxide, and the drying of the l0 paste must be so regulated that they progress parallel. Otherwise, the paste, losing its volume by drying, will crack, and interspaces will be formed between the coating and the plate or grid, thus shortening the life of the battery. Moreover, when drying the paste, as it does not undergo any structural chan e, as hardening of cement by hydration, it is very diificult to make batteries that last long. I

and spongy lead suboxide of an apparent specific gravity of not more than 3 1s utilized as active material, and is applied to the plate, or grid, after kneading the same in water or dilute sulphuric acid, into. a paste. After application to the plate'or grid and when drying, such paste will be acted upon by water and oxygen in the air, and'will be converted into lead hydroxide and will increase its volume whlch, counteracting the shrinkage due to drying, removes the drawback of cracking. Moreover, whenthe suboxide is converted into hydroxide, av marked place and the paste hardens inthe same condition as cement hardens by hydration, and thus very durable batteries canbe manufactured. The lead suboxide used in this invention,

is formed by reducing metallic lead into fine, spon powder b mechanical abrasion. It is chie y comp According to this invention, a very fine changein the construction of the paste takes I of leadsuboxide, but is sometimes intermingled, from the nature Application filed ebruar 20, 192 Serial 110. 620,267.

of the process to manufacture it with 1 to 40% metallic lead powder. Also, from the nature of lead suboxide, it is slowly converted, while being manufactured or when it is left exposed to the air, into monoxide, and consequently it is sometimes intermingled with lead monoxide. But'such lead monoxide formed by oxidation in a warm room in the atmosphere retains, diiferent from monoxide formed by igniting lead powder, an apparent specific gravity ofthe suboxide used asthe material, easily hardens, is rich in activity and forms a durable plate. Consequently, even when lead suboxide is slowly oxidized whileit is stored, such oxide in no way obstructs the carrying of this invention into efiect.

Thus, in my invention, the lead suboxide used as material, ismanufacturedtwithout using any water; .there is little chance for any impurities to intermingle therewith during the procem of manufacture; and

there is no necessity of adding to the lead I suboxide when kneading the same into paste in order to lengthen the life thereof any drug prejudicial to batteries. Moreover, the process of forming may'be entirely dispensed with, plates being formed when 0 arged' withelectricity for the battery is the first time. .Of course, the process of 'fforming may be carried out according to the ordina method.

To explain my invention more in detail,

the following is an example of carrying it into practice Pieces of metallic lead are reduced to fine powder by causing the pieces to .rub against one another in a slowly revolved drum, and the powder is then ex osed to the air. Then take 300 grammes 0 such powder, which is very fine and light, having an apparent specific gravity of not more'than 3, mix it with 45 cubic centimeters of water, knead the mixture and 'with the paste thus ready to used for storage batteries. .'Ap-.

m a vessel of known capacity with lead sub oxide powder lay causing the powder to fall from. a. sieve, smooth" the surface softly without essing, and weigh it. Then, take formed coat or fill the ordinary plates "or", grids. When-the platesare dry, they are weight 0 waterof 4. 0. of the same volume,

and divide the weight of the former by that of the latter, and the quotient is the apparent specific gravity sought.

Claims: r

1. The process of preparing plates for storage batteries, which consists in reducing metallic lead to a fine powder, exposing said powder to the air, mixing. the same with liquid, kneading the mixture into the form 10 of a paste, coating the plates with saidpaste, and drying the same thereby to convert the lead .suboxide into lead monoxide and lead hydroxide.

2. The proces of preparing plates for storage batteries, which consists in reducing metallic lead to a fine powder, exposing the same to the air, mixing 300 grammes of i said powder with 45 cubic centimeters of Water, kneading the mixture to form a paste,

coating the plates with said paste, and drying the same thereby to convert the lead suboxide into lead monoxide and lead by droxide.

3. A process of manufacturing plates for storage batteries, consisting in kneading lead suboxide intermingled with lead monoxide and suflicient liquid to form a paste and applying the same to or filling therewith the plates or grids.

4. A process of manufacturing plates for storage batteries, consisting in kneading lead suboxide intermingled with lead monoxide,'

metallic lead, and suflicient liquid to form a paste, and applying the same to or filling therewith the plates or grids.

In testimony whereof I have signed my name to this specification.

GENZO SHIMADZU. 

